US6485098B1 - Restraint system for a school bus seat - Google Patents

Abstract

A passenger restraining harness and support assembly for use with a bench seat mounted in a vehicle. The bench seat includes a frame having a seat support portion with a front portion and a rear portion, a seatback portion coupled to the seat support portion, and legs or supports anchoring the seat to the vehicle. A harness support assembly includes a tower member with a slotted bottom end pivotally coupled to the rear of the seat support, a connecting member having one end adapted to fit into the slot in the tower member and a second end connected to the front of the seat support portion, a belt guide connected to the top of the tower member, and an anchor wing connected to the connecting member. A belt or harness attaches to the support assembly.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of co-pending U.S. patent application Ser. No. 09/479,197 filed Jan. 7, 2000, and titled Restraint System for a School Bus Seat. U.S. Ser. No. 09/479,197 is a continuation-in-part of U.S. Ser. No. 09/183,088 filed Oct. 30, 1998, and titled Restraint System for a School Bus Seat, now U.S. Pat. No. 6,123,388. The disclosures of these prior applications are hereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention is in the field of seat belts used to provide a protective passenger environment.

DESCRIPTION OF THE PRIOR ART

Conventional seat belt systems combining a lap belt and an upper torso belt are well known. These three-point restraint systems are usually used with seats offering rigid support for the belts. As typically used in a vehicle, the three-point restraint system consists of single belt having its opposite ends mounted to a pair of retractors with a seat belt tongue connected to the belt intermediate to the belt ends. The tongue may be swung across the person and engaged with a buckle affixed to the seat thereby positioning one portion of the belt across the lap and another portion of the belt across the upper torso. In some systems, only one end of the belt is mounted to a retractor while the other end is anchored to the seat or vehicle. Seat belts are active restraint devices, requiring a passenger to actively engage the restraints for them to be effective.

School bus passenger seats usually do not employ active restraint safety devices, but instead rely on a passive restraint seat design. School bus passenger seats are built to specifications conforming to the safety standards set by the National Highway Traffic Safety Administration, DOT. These are codified as 49 C.F.R. Ch. V, .sctn. 571.222, Standard No. 222, and require that the seat back bend or deflect forward when a force is applied to the rear of the seat back. The code further specifies that 4000 W inch-pounds of energy must be absorbed within a maximum forward deflection of the seat back of 14 inches and 2800 W inch-pounds be absorbed within a maximum rearward deflection of the seat back of 10 inches where W represents the number of seating positions for which the seat is designed. 49 C.F.R., Ch. V, .sctn. 571.222, S5.1.3-5.1.4. The code specifies a passive restraint system, and does not require any sort of active restraints, such as a two-point passenger restraining lap belt or a three-point passenger restraining lap belt and torso harness combination. Children riding the school bus are protected in head-on collisions by the seat back in front of them deflecting forward and absorbing some of their forward momentum.

Vehicles with deforming or deflecting seats provide special problems regarding the integration of active restraint seat belt systems. Passive restraint systems are designed to protect a passenger who has been thrown forward by having the impacted seat back deflect upon impact of the thrown passenger and absorb some of their momentum. In a school bus seat combining active and passive restraint systems, both of the restraint systems have to be able to perform their functions and the seat must still conform to the regulations set forth in 49 C.F.R.

In U.S. Pat. No. 5,746,476, there is disclosed an automotive seat having a tower frame associated with the harness to transmit impact loads to the floor. Despite the prior devices, there is still a need for increased protection for children riding the school bus in an emergency or crash situation. The addition of an active restraint system, such as a three-point lap belt and torso harness combination, would provide enhanced passenger protection in a head-on crash as well as providing passenger protection in a broadside collision and/or roll situation. Disclosed herein is a three-point lap belt and torso harness passenger restraint system that is compatible with the pivoting and deflecting seats required by 49 C.F.R.

A further need is to provide a restraint system for a school bus seat that is operable to remove slack in the belt during rapid vehicle deceleration. The conventional method is to employ pretensioner devices connected to the belt which rapidly withdraw the belt once a pyrotechnic charge fires upon sensed vehicle deceleration. Such pretensioner devices may be mounted beneath the seat. In the case of a school bus seat, the addition of a pretensioner device reduces storage space beneath the seat. In lieu of a pretensioner device, we have devised a device built into the seat to automatically take up slack in the belt as the restrained passenger moves forward with the tower frame assembly during vehicle deceleration.

SUMMARY OF THE INVENTION

One embodiment of the present invention is a three-point lap belt and torso harness passenger restraint system for a school bus having forward-facing bench seats fastened to the vehicle floor and having forward pivoting and deflecting seat backs, comprising a lap belt and torso harness combination connected to a support structure positioned within the bench seat and coupled to the floor of the vehicle. The support structure includes a connecting member connected to the seat support and a tower member pivotally coupled to the seat support. The tower member includes a vertical slot that accepts one end of the connecting member, and both the tower member and the connecting members have coincident apertures through which a portion of the seat support may extend. The tower member lies in the plane of the seat back and is adapted to pivot through a predetermined angle around the rear of the seat support. The relative dimensions of the intersecting slot and connecting member determine the pivot angle.

In another embodiment of the present invention, a three-point lap belt and torso harness passenger restraint system for use with attached school bus seats having forward deflecting seat backs, comprises a three-point harness combination connected to a support structure coupled to the seat support and the vehicle. The support structure includes a connecting member connected to the seat support, a tower member connected to the connecting member and pivotally coupled to seat support, and a crossbar member connected to the front and rear portions of the seat support. The lower end of the tower member is connected to the connecting member, and the tower member is intermediately pivotally mounted to a seat support member. The tower member extends into the seat back and is adapted to pivot through a predetermined angle in response to a force acting thereon. As in the previous embodiment, a belt or harness system attached to the pivoting support structure allows a passenger to pivot forward sufficiently to allow the seat back to deflect according to specification, while holding the passenger in the seat.

In another embodiment of the present invention a restraint apparatus for a passenger in a vehicle having a seat frame mountable to the vehicle. The frame includes a seat portion and a back portion. The back portion has a bottom end portion, and a top end portion with the back portion pivotable forwardly about the bottom end portion toward the seat portion upon crash force applied to the back portion. A retractor has a web extending therefrom through a web guide. The web has a chest portion and a lap portion positionable across a passenger located on the seat portion. The retractor has an unlocked position and a locked position. A first lock is mounted to the web and a second lock is mounted adjacent to the seat portion and lockingly engaged with the first lock. A tower is mounted to the frame and movable with the back portion. A web tensioning arm is mounted to the frame and is moved by the tower to engage the web to take up slack in the web as the arm moves upon crash of the vehicle.

It is an object of the present invention to provide an active restraint system compatible with existing passive restraint school bus seats and the present Federal safety regulations.

A further object of the present invention is to provide an active restraint system for school bus passengers.

Related objects and advantages of the present invention will be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1ais a perspective view of a bench seat frame incorporating a first embodiment of the present invention.

FIG. 1bis the same view as FIG. 1awith the addition of an attached seat belt assembly.

FIG. 2ais a partial side elevation view of the embodiment of FIG.1.

FIG. 2bis a front elevation view of the tower member of the embodiment of FIG.1.

FIG. 2cis a side elevation view of the embodiment of FIG. 1 coupled to a bench seat frame.

FIG. 2dis a side elevation view of the embodiment of FIG. 1 mounted below a bench seat frame.

FIG. 3ais an enlarged fragmentary front elevation view of the slot in the tower member of the embodiment of FIG.1.

FIG. 3bis an enlarged side fragmentary elevation view of the slot in the tower member of FIG. 3a.

FIG. 3cis an enlarged side fragmentary elevation view of the intersection of the tower member and the connecting member, showing the rotation of the tower member.

FIG. 4ais a perspective view of a bench seat frame incorporating a second embodiment of the present invention.

FIG. 4bis the same view as FIG. 4awith the addition of an attached seat belt assembly.

FIG. 5ais a side elevation view of the embodiment of FIG. 4a.

FIG. 5bis a side elevation view of the embodiment of FIG. 4b.

FIG. 5cis a partial front elevation view of the embodiment of FIG. 4b.

FIG. 6ais a side elevation view of the connecting member of the embodiment of FIG. 4a.

FIG. 6bis a front elevation view of one vertical piece of the tower member of FIG. 4a.

FIG. 6cis a side elevation view of one vertical piece of the tower member of FIG. 4a.

FIG. 7 an enlarged perspective view of the crossbar member of the second embodiment of FIG. 4a.

FIG. 8 is a top plan view of the embodiment of FIG. 4b.

FIG. 9 is a perspective view of the illustrative embodiment of the bench seat frame with a belt slack take-up device.

FIG. 10 is a fragmentary enlarged perspective view of the left side of the bench seat frame of FIG.9.

FIG. 11 is a fragmentary cross sectional view of the seat portion and back portion of the frame in a pre-crash condition taken generally along theline11—11 of FIG.9 and viewed in the direction of the arrows.

FIG. 12 is the same view as FIG. 11 only showing the back portion tilted forward in a crash condition with belt slack taken up.

FIG. 13 is a fragmentary top view of the bench seat of FIG.10.

FIG. 14 is a cross sectional view taken generally along theline14—14 of FIG. and viewed in the direction of the arrows.

FIG. 15 is a perspective view of an illustrative embodiment of the seat including the seat cushion.

FIG. 16 is a side perspective view of the seats depicted in FIGS. 9 and 15.

FIG. 17 is a side schematic view of an illustrative embodiment of a system of seats depicted in FIGS.9 and15.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring now more particularly to the drawings, FIGS. 1 through 3 show a three-point restraint system120 incorporating a first and illustrative embodiment of the present invention. Therestraint system120 is designed to restrain two passengers sitting side by side. Therestraint system120 includes atower member121 movably coupled to a connectingmember122, and is adapted to be mounted to a conventional school buspassenger seat frame123.Tower member121 is adapted to move independently relative toseat frame123. Preferably,tower member121 is adapted to pivot relative toseat frame123. The members comprisingrestraint system120 are formed from steel or any convenient structural material.Seat frame123 includes aseat support portion124 connected to a seat backportion125 and also connected to aleg portion126 adapted to be affixed to a surface, such as the floor of a school bus.Seat support portion124 is typically formed from one or morebent metal tubes127 and includes afront portion128 and arear portion129.Seat support portion124 may be wrapped or embedded in a cushion upon which a passenger may sit. Seat back125 portion, also formed frombent metal tubes127, may likewise be cushioned.

Connectingmember122 is formed having a rectangularcross-sectional shape130, although in otherembodiments connecting member122 may have any convenient cross-sectional shape.Tower member121 has atop end131 and abottom end132.Bottom end132 includes aslot133 shaped to accept connectingmember122 and a pair ofparallel apertures134 perpendicular to slot133 through whichrear portion129 ofseat support portion124 may pass to coupletower member121 toseat frame123.Tower member121 lies in the plane defined by seat backportion125 with the top end oftower member121 extending substantially into seat backportion125.

Connectingmember122 has afront end137 and arear end138, and includes arear aperture140 through whichrear portion129 may extend to mount connectingmember122 toseat123. Connectingmember122 is inserted intoslot133 intower member121. In operation,tower member apertures134 may be aligned coincident with connecting memberrear aperture140 enablingrear metal tube129 to be passed therethrough,coupling tower member121 and connectingmember122 toseat support portion123 and to each other. Connectingmember122 further includesfront aperture141 through whichfront portion128 extends, mounting connectingmember122 toseat123. (See FIG. 2c) Alternatively, connectingmember122 may be affixed toseat support portion124 by any convenient fastening means. (See FIG. 2d)

In operation, connectingmember122 lies in the plane defined byseat support portion124. Bothtower member121 and connectingmember122 may be embedded in cushions that simultaneously provide passenger comfort and preventrestraint system120 from moving or jiggling. In the illustrative embodiment,tower member121 is pivotally coupled toseat support portion124. A stop means operable to limit the movement oftower member121 is provided by the presence of connectingmember122 inslot133, which limits the pivot angle139 (see FIG. 3c) through whichtower member121 may be rotated. While the illustrative stop means is connectingmember122filling slot133, any convenient stop means may be used. It is preferable that thepivot angle139 through whichtower member121 may pivot is acute. It is more preferable that thepivot angle139 be about 17 degrees, corresponding to the maximum allowed deflection of seat backportion125 caused by two unbelted passengers striking seat back125 from behind and two belted passengers pulling ontower member121 from the front. Slot133 preferably extends throughtower member121 at a slight angle to the normal, such that when connectingmember122 engagestower member121 connectingmember122 may rest in the horizontal plane ofseat support portion124 whiletower member121 remains tilted backwards a few degrees to the vertical. (See FIG. 3c) In this embodiment, the dimensions of connectingmember122 and slot133 are sized relative to each other such thattower member121 may rotate forward through a maximum of 17 degrees. (See FIG. 3c)

Restraint system120 also includesanchor wing143 connected to connectingmember122. Aseat belt anchor144 is fixedly attached to anchorwing143, becoming one point of a three-point restraint. (See FIG. 1b)Seat belt anchor144 connectslap belt145 terminating in a tongue146 toseat frame123. Alternatively, two seat belt retractors could be attached to bothanchor wings143, retractably connectinglap belts145 thereto.Restraint system120 further includes abuckle147 fixedly attached toseat support portion124 and adapted to lockingly engage tongue146.Restraint system120 further includes a pair ofguides148, such as, a conventional D-loop, attached near the top oftower member121. A pair oftorso belt retractors149 are connected to towermember121, each housing atorso belt150 and becoming the second point of the three-point restraint. Thetorso belt150 is extended upwardly throughguide148 and downwardly across the torso of a seated passenger. The extending end oftorso belt150 also connects to tongue146. When tongue146 is locked inbuckle147,buckle147 becomes the third point of the three-point restraint. Alternatively, a single belt (not shown) may extend betweenretractor149 andanchor144 with a tongue (not shown) slideably mounted intermediate thereto.

In operation, the invention adds active passenger restraint protection to the passive restraint already provided by the deflecting school bus seats.Tower member121 does not interfere with the passive restraint function of the seat back125, sincetower member121 is adapted to pivot forward along with the seat back125 in response to a rear impact. Seat backportion125 deflects forward in response to a forward force applied thereto consisting of a passenger located rearward of the seat backportion125 impacting seat backportion125 and/or a forward force applied to supporttower121 viatorso belt150 by a seated passenger pulling against thetorso belt150.

Another embodiment of the present invention is shown in FIGS. 4 through 8. In this embodiment, therestraint system220 includes atower member221, a connectingmember222, and acrossbar member252 and is adapted to be mounted to aseat frame223.Seat frame223 includes aseat support portion224 connected to a seat backportion225.Seat frame223 is also connected to aseat leg portion226 adapted to be affixed to a surface, such as a school bus floor.Seat support portion224 is made of bent metal tubing and includes afront portion228.Rod member229 extends transversely across seat backportion225 substantially within the plane defined byseat support portion224.Seat frame223 may be wrapped or embedded in cushioning material to provide passenger comfort.

Harness support assembly is made up oftower member221, connectingmember222, andcrossbar member252, and is mountable toseat frame223. When so mounted,tower member221 lies substantially in the plane defined by seat backportion225, and extends through the plane defined by theseat support portion224.Rear end238 of connectingmember222 connects to towermember221 below the plane defined byseat support portion224.Front end237 of connectingmember222 connects tofront portion228 ofseat support portion224. In this embodiment,front end237 of connectingmember222 features front aperture241 (FIG. 6a) through whichfront portion228 ofseat support portion224 extends.Tower member221 is pivotally mounted toseat support portion224 atpivot point253. In order to accommodate two passengers, a pair of harness assemblies is provided, each with atower member221, connectingmember222 andcrossbar members252 and254.

Rod member229 extends throughtower member221 andcrossbar members252 and254. In the illustrative embodiment,crossbar member252 includes two parallel plates lying substantially within the plane of theseat support portion224 and extending from thefront portion228 to therod member229. Proximal end255 (FIG. 7) ofcrossbar member252 includes substantiallycircular apertures265 through whichfront portion228 ofseat frame223 extends.Distal end256 ofcrossbar member252 includescircular apertures266 through whichrod member229 extends atpivot point253. In this embodiment a crossbar coupling member257 (FIG. 8) connects the plates ofmember252. Likewise, a second connectingmember254 is provided consisting of two plates being connected to the second tower member in the same manner as described formember252.

Tower member221 comprises a pair of substantially vertically disposed members258 (FIG. 5c), connected bytower coupling member260. In other embodiments,tower member221 may comprise a different number of vertical members. Likewise, in thisembodiment connecting member222 comprises two interconnected portions259 (see FIG. 5c).

Each connectingmember222 includes a slot270 (see FIG. 4a) atrear end238. Apin272 extends throughslots270 with the opposite pin ends fixed tovertical members258. The pin slideably connectsmembers222 to thetower221. In normal operation,tower member221 rests within the plane of the seat back225, tilted slightly rearwards with thepin272 positioned at the forward end273 (see FIG. 6a) of theslot270. As tower member pivots aboutpivot point253, pin272 moves towards the rear ofslot270. Pivoting oftower member221 is halted whenpin272 reachesrear end274 ofslot270. The length ofslot270 determines the maximum angle through whichtower member221 may pivot. In this embodiment, the length of theslot270 is such that the maximum angle through which thetower member221 may pivot is 17 degrees.

As in the previous embodiment,restraint system220 also includesguides248 connected near thetop end231 oftower member221. Seat belt retractors249 (FIG. 5b) are fixedly attached to the two vertical members oftower221. Eachseat belt retractor249 house atorso belt250, which connect to atongue246 in turn connected tolap belt245.Restraint system220 also includes abuckle247 fixedly attached toseat support portion224 and adapted to lockingly engagetongue246.Torso belt250 is extended upwardly fromtorso belt retractor249 throughguide248 and downwardly across the torso of a seated passenger whilelap belt245 extends horizontally across the passenger's lap. Alternately, a single belt (not shown) may extend betweenretractor249 to anchor244 with a belt tongue slideably mounted intermediate thereto.

Many variations are contemplated and included in the present invention. In addition to those described in relation to the above embodiments, the present system contemplates including means for preventing premature forward deployment of thetower member221 relative to the seat back. For example, the top end oftower221 may be connected to seat backportion225 limiting relative motion therebetween until sufficient force breaks the top end of the tower apart from the seat back portion.

The preferred embodiment of the restraint system is shown in FIGS. 9-15.School bus seat300 includes amain frame304 with a pair iffront legs301 and302 and a pair ofrear legs303. The legs extend upwardly being joined tomain frame304 having afront member305 integrally joined to a pair if rearwardly extendinghorizontal members306,307, and309. Atubular member308 has opposite ends integrally joined toside members306 and307 with center member309 extending between and integrally joined tofront member305 andcylindrical member308. A pair offlanges310 and311 are integrally joined tot he cylindrical member38 and the opposite sides of member309.

Frame304 forms the frame for the seat portion of the seat whereas asecond frame312 forms the frame for the back portion of the seat.Frame312 includes a horizontally extendingtubular portion313 integrally joined to a pair of downwardly extendingtubular portions314 and315 forming a single frame, in turn, having bottom ends integrally joined to frame304.Frames304 and312 are located within the cushion respectively of the seat portion and back portion of the seat.tubular portions314 and315 are rigid; however, will bend forward as forward impact pressure is applied to the back portion of the seat forcing the back portion of the seat about its bottom end toward the seat portion of the seat.

Upwardly extendingtowers316 and317 are located immediately inward offrame portions314 and315.Tower316 is mounted to and betweenplates355 and356 (FIG. 10) which have holes380 (FIG. 9) through whichtube308 freely extends allowing the tower to pivot ontube308 in the direction ofarrow322 to and from the seat portion offrame304.Tower317 is mounted in a similar manner. The top ends oftowers316 and317 are joined together by horizontally extendingmember323.Flanges324 and325 are integrally attached to the top ends oftowers316 and317 and provide guides through which the webs extend.Wall339 is fixedly mounted to frame312 andmember323 preventingmember323 from moving behindframe312.Wall339 breaks when forward force is applied to either frame312 ortowers316/317 allowing independent movement oftowers316/317 relative to frame312.

Box constructions381 and382 extend between and are fixedly attached torear member308 andfront member305. Each box construction supports a plurality of stationary bearings and a web retractor.Box construction381 and382 include respectivelyinner plates328 and329 having rear ends integrally secured tomember308 and front ends fixedly secured tomember305. Likewise,box constructions381 and382 have outwardly located members, respectively330 and331 integrally secured and extending betweenmembers308 and305.Retractor plates326 and327 are secured respectively tomembers328 and330 andmembers329 and331. Two conventional inertia locking retractors are respectively mounted to and beneathplates326 and327 with the web of each retractor extending rearwardly towardtubular member308.

Eachbox construction381 and382 have three stationary bearings with their opposite ends fixedly attached to the inner member and outer member of each box construction. For example,bearings332,333 and334 (FIG. 10) have first ends fixedly attached toinner member328 and second ends fixedly attached toouter member330. Retractor335 (FIG. 11) is fixedly attached to and beneathplate326 and hasweb336 extending rearwardly over stationary bearings332-334 but beneathmovable bearings337 and338.Web336 continues aroundtubular member308 extending upwardly behindtower316 to the top of the tower. The web then extends over a bearing surface at the top of the tower and freely through a loop, such as flange324 (FIG. 9) with thedistal end340 ofweb336 being fixedly attached to therear corner341 offrame304.

A conventional seatbelt buckle tongue342 is slidably mounted toweb336 and is locking engagable with a conventionalseat belt buckle343, in turn, attached byweb344 toflange310. Thus, withweb344 extending upward through the seat cushion,tongue342 may lockingly engagebuckle343 forcing the web across the shoulder and chest of the occupant residing on the seat and then across the lap of the occupant.Web336 therefore includes achest portion395 and alap portion345 when the tongue is secured to the buckle.Web336 extends outward of the cushion forming the back portion of the seat. An identical retractor web combination is provided on the right side of the seat as viewed in FIG. 9 relative to tower317 andbox construction382.

When force is applied in a forward direction to the rear of the seat by a passenger located behindseat300,frame portions314 and315 are pushed forward bending and pivoting about their bottom ends.Frame portions314 and315 are sufficiently rigid to hold the seat back portion in an upright position but sufficiently weak to bend when rearward force is applied thereto thereby being in compliance with the safety standards set by the National Highway Traffic Safety Administration as discussed in the Description of the Prior Art herein. If aseat300 is occupied then the forward motion of the passenger onseat300 will apply forward force viaweb336 to tower316 rupturingbreakable wall339 allowing the tower to pivot independent offrame312.Towers316 and317 are pivotally mounted totube308 thereby allowing the towers to pivot forward towards the seat portion or frame304 of the seat. A pair ofstop flanges350 and351 are fixedly attached respectively totowers316 and317 and project forwardly of the towers. The stop Flanges are designed to allow only a limited amount of forward pivotal motion of the towers. Once the stopflanges contact members330 and331, additional forward pivotal motion of the towers andframe312 is prevented.

Stopflange350 will now be described it being understood that a similar description applies to stopflange351. Stopflange350 includes a pair of spaced apartwalls355 and356 (FIG. 10) fixedly secured to the opposite sides of the bottom oftower316. Awall357 has opposite ends fixedly attached towalls355 and356 and extends therebetween.Wall357 is elevated and spaced apart from the top surface ofmember330 when the tower is in the erect or normal position.Wall357 is spaced apart from the top surface ofmember330 to only allow a predetermined amount of forward pivotal motion of the tower unit the wall contacts the top surface ofmember330 thereby preventing further pivotal motion of the tower andframe312. The amount of forward pivotal motion of the tower is designed to be in accordance with the deflection requirements of the National Highway Traffic Safety Administration specifications as previously discussed.

A web slack take-up device is mounted within eachbox construction381 and382. The web slack take-up device360 (FIG. 13) positioned withinbox construction381 will now be described it being understood that a similar description applies to the web slack take-up device positioned withinbox construction382.device360 includes abottom wall361 secured to a pair of upwardly extendingside walls362 and363 between which are fixedly mounted a pair ofbearings337 and338.Web336 extends betweenbearings337 and338 and the three stationary bearings332-334 (FIG.11). The proximal ends ofwalls362 and363 are fixedly attached tosleeve318 and are designed to pivot aroundtube308.Tube308 extends freely through sleeve318 (FIG. 9) andsleeve319 of the slack take up device mounted withinbox construction382.Walls362 and363 have cut outportions386 and387 (FIG. 11) preventing interference ofwalls362 and363 withstationary bearings333 and332 when the tower is in the erect position.

Towers316 and317 cause the slack take-up device to pivot downwardly as the towers pivot toward the seat portion of the seat; however, pivotal movement of the towers in an opposite direction away from the seat portion does not cause the slack take-up devices to pivot to their original positions. Each tower includes a projection contactable with a projection extending outwardly fromsleeves318 and319. For example,tower316 includes projection370 (FIG. 14) extending inwardly whereassleeve318 includesprojection371 extending outwardly towardtower316. Thus, whentower316 pivots in a counter clockwise direction, as viewed in FIG. 14,projection370contacts projection371 causingsleeve318 andbearings337 and338 to pivot therewith in a counter clockwise direction removing slack from the web. Movement oftower316 in a clockwise direction simply movesprojection370 apart fromprojection371 without movingsleeve318.

In operation, upon the occurrence of a crash, forward force may or may not be applied to the rear of the seat by the passenger located behind the seat. Forward force is applied however toweb336 by the occupant resting uponseat300. Withretractor335 locked as the result of sensed deacceleration, forward force is applied via the web totowers316 and317 causing the towers to pivot forwardly toward the seat portion of the seat.Stops350 and351 oftowers316 and317 limit the forward pivotal motion of the towers. Simultaneously, the web slack take-up devices within eachbox construction381 and382 pivot downward resulting inbearings337 and338 of each web slack take-up device contacting the respective web of each retractor forcing the webs into a serpentine path as depicted in FIG. 12 thereby removing any slack from the webs. Even if an occupant is not resting uponseat300, impact of a passenger behindseat300 upon the back portion ofseat300 will causeframe312 to bend and pivot toward the seat portion of the seat to the maximum angle permitted bystops350 and351.

FIG. 15 illustratesseat300 which has a seat cushion orother enclosure386enclosing frame304, a cushion orother enclosure383enclosing frame312 and a center cushion orother enclosure384 enclosingtowers316 and317 along withmember323.Slots385 are provided incushion384 for the webs to extend through.Cushion383 is indented to receivecushion384 to allow thecenter cushion384 to pivot forward independent ofouter cushion383 when force is applied totowers316 and317 by occupant force being applied to the webs.

FIG. 16 illustratesseat300, as depicted in FIGS. 9 and 15, with thecenter cushion384 pivoted forward of theouter cushion383. As previously described, thecenter cushion384 encloses upwardly extendingtowers316 and317, each tower having a top portion and a bottom portion, and horizontally extendingmember323 therebetween, which together form a pivotablethird frame390 for supporting thecenter cushion384 and for supporting and guiding theweb belt336 as depicted in FIGS. 9,15 and16. Theframe390 together withcenter cushion384 form a seat back for supporting a passenger inseat300, which seat back moves together substantially as a unit as shown in FIG.16. As described above and depicted in FIGS. 9,15 and16,seat cushion386 enclosesframe304 to form the seat portion or seat bottom for supporting a passenger.

Referring to FIG. 17, asystem398 ofseats300, as previously described and depicted in FIGS. 9,15 and16, is illustrated with the seats in a longitudinally oriented row. Thecushion383 together withenclosed frame312, as described and depicted in FIGS.9 and15-17, form a passenger restrainer for anunbelted passenger396 or a beltedpassenger397 sitting in anyseat300 situated behind anyother seat300 as depicted in FIG.17. As illustrated in FIGS. 15 and 16, thecushion383 has a rearwardly facingsurface388. As illustrated in FIGS. 16 and 17, thecushion383 also has a forwardly facingsurface389 of thecushion383 facing forward.

Referring to FIG. 17, the operation ofsystem398 will be expanded upon. As already noted, when apassenger396,397 sitting behind aseat300 applies a force forwardly toward rearwardly facingsurface388 ofseat300, as in the event of a crash, then theframe portions314 and315 offrame312 deform, thereby absorbing the energy of the forwardly movingpassenger396,397. As previously explained, if a forwardly movingpassenger397 is wearing aseat belt336, then the force of a crash will move thepassenger397 againstweb belt336 with force sufficient to rupturebreakable wall339, or other frangible retaining means known to one skilled in the art, allowingframe390 and associated enclosingcushion384 to pivot forward independent offrame312 until a stop mechanism, such as previously describedstop flanges350 and351 in cooperation withcontact members330 and331, stops the forward movement offrame390 andcushion384. As previously noted, although thebelt336 and associated take-updevice360 absorb some of the passenger's397 forward momentum, it will be appreciated that, depending on the size of beltedpassenger397 and the force thatpassenger397 applies on theweb336, thepassenger397 may or may not impactsurface388 in a crash. It will also be appreciated that the frangible retaining means339 may be designed to rupture at varying amounts of force. Also, because the forward movement offrame390 and cushion384 is independent offrame312,frame312 and associatedcushion383 remain in place to absorb the energy of apassenger396 or397, whether belted or not, sitting in the seat behind the seat of a beltedpassenger397. The phantom rendition ofcushion383 in FIG. 17 depicts thecushion383 prior to contact by thefowardly moving passenger396.

If apassenger396 is not wearing abelt336, then a crash will not move thepassenger396 against theweb336 and the retaining means339 will therefore not break. In such a case, cushion384 will remain withincushion383 thereby pivoting forward withframe portions314 and315 and cushion383 in the event that a passenger sitting behind impacts therearwardly facing surface388. Similarly, if a passenger sitting behind an empty seat applies forward pressure against the rearwardly facingsurface388 of such an empty seat, then frame390 and cushion384 will remain withinframe312 and cushion383 and will not impede the movement of, but rather, will move forward with,frame portions314 and315.

Many advantages flow from use of the preferred embodiment of the invention. For example, webbing from a restrained occupant onseat300 simultaneously applies load totowers316 and317 causing the towers to pivot forward while applying tension load to the entire webbing length. That is, slack is removed from the webbing surrounding the occupant by the downwardly pivoting slack take up devices. Tension of the restraint is therefore increased around the occupant. A large mechanical advantage is provided by the lengths of the towers which exceed the length of the slack take up devices. As the towers pivot downwardly along withbearings337 and338, the tension increases proportionately thereby decreasing the occupant forward acceleration rate proportionally. The increasing tension in the lap portion of the web centers the occupant in proper seating position during forward impact movement. Likewise, additional tension in the web controls kinematic motion of the restrained occupant so that the motion is straight during forward motion and straight during rebound motion. The added tension in the web will further cause the occupant to be in proper seating position after the occupant motion is complete.

The system of FIG. 9 will not cause additional stiffness to the seat back when the occupant is unrestrained or the seat is unoccupied and thus, maintains the energy management capability for any unrestrained occupant located behindseat300. The system preserves the under seat clearance for other vehicle features. Likewise, the system will not require additional structure to the seat back when the restrained or unrestrained occupant is forced rearward into the seat back during impact.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that all changes and modifications that come within the spirit of the invention are desired to be protected.

Claims (20)

What is claimed is:

1. A vehicle passenger seat restraint system comprising:

a passenger seat frame mounted to a vehicle and having a vertically extending portion,

a seat for supporting a passenger and having a seat bottom fixedly mounted to the seat frame and a seat back moveably mounted to said seat frame adjacent the vertically extending portion,

a substantially rigid seat belt supporting member rigidly mounted to said seat back,

said supporting member having a top portion and a rigid bottom portion,

wherein said rigid bottom portion and said seat frame define a cooperative stop mechanism, and

wherein said stop mechanism limits movement of said seat back relative to said seat frame in at least one direction.

2. The seat structure ofclaim 1, wherein the mounting of the seat back to the seat frame utilizes a pivot connection to allow pivoting of the seat back relative to the seat frame.

3. The seat structure ofclaim 1, further comprising restraining means on the seat frame to restrain initial movement of the seat back with respect to the seat frame.

4. The seat structure ofclaim 3, wherein the restraining means is frangible to permit movement of the seat back with respect to the seat frame.

5. The seat structure ofclaim 1, further comprising a stop for limiting the extent of movement of the seat back relative to the seat frame.

6. The seat structure ofclaim 5, wherein the stop is defined by cooperating elements on the seat frame and the seat back.

7. The seat structure ofclaim 1, further comprising a seat belt supported on the seat belt supporting member.

8. The seat structure ofclaim 7, wherein the seat belt has an end mounted to the seat frame.

9. The seat structure ofclaim 8, wherein the end is mounted to the seat bottom.

10. The seat structure ofclaim 7, wherein the seat belt has an end mounted to the seat belt supporting member.

11. A seat structure for mounting a passenger restraint seat belt comprising:

a seat frame for mounting to a vehicle,

a rear passenger restrainer rigidly mounted on the seat frame to restrain movement of a rear passenger,

a seat having a bottom and a seat back carried by the seat frame for supporting a person,

said seat back mounted to said seat frame, and moveable as a unit away from said seat frame and said rear passenger restrainer,

a seat belt support fixedly mounted to the seat back and moveable relative to the seat frame and rear passenger restrainer upon movement of said seat back relative to the frame.

12. The seat structure ofclaim 11, wherein the mounting of the seat back to the seat frame utilizes a pivot connection to allow pivoting of the seat back relative to the seat frame.

13. The seat structure ofclaim 11, further comprising restraining means on the seat frame to restrain initial movement of the seat back with respect to the seat frame.

14. The seat structure ofclaim 13, wherein the restraining means is frangible to permit movement of the seat back with respect to the seat frame.

15. The seat structure ofclaim 11, further comprising a stop for limiting the extent of movement of the seat back relative to the seat frame.

16. The seat structure ofclaim 15, wherein the stop is defined by cooperating elements on the seat frame and the seat back.

17. The seat structure ofclaim 11, further comprising a seat belt supported on the seat belt support.

18. The seat structure ofclaim 17, wherein the seat belt has an end mounted to the seat frame.

19. The seat structure ofclaim 18, wherein the seat belt end is mounted to the seat bottom.

20. The seat structure ofclaim 19, wherein the seat belt has an end mounted to the seat frame.

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